Some vehicles are configured to operate in an autonomous mode in which the vehicle navigates through an environment with little or no input from a driver. Such a vehicle may include one or more sensors that are configured to sense information about the environment. The vehicle may use the sensed information to navigate through the environment.
For example, if an output of the sensors is indicative that the vehicle is approaching an obstacle, the vehicle may navigate around the obstacle. Additionally, a vehicle may sense information about traffic signs and traffic signals. For example, traffic signs may provide regulatory information or warning information while traffic signals positioned at road intersections, pedestrian crossings, and other locations may be used to control competing flows of traffic.